Photographic emulsions sensitized with merocyanine dyes containing a 5(4)-thiazolone nucleus



Oct. 26, 1954 P, AUBERT ETAL 2,692,829

PHOTOGRAPHIC EMULsIoNs SENSITIZED WITH MEROCYANINE DYES CONTAINING A 5(4)-THIAZOLONE NUCLEUS Filed Feb. l?, 1951 I HWII IIII IIIMHII III! IIII 300 400 .foo ao 70o rrp FIG'. 2

FIG. 3.

PER AUBERT EDWARD B..IQ\TOTT INVENTORS MKM ATTORNEY Q57 AGENT Patented Oct. 26, 1954 PHOTOGRAPHIE EMULSONS SENSITIZED WITH MEROCYANIN A 5 (Ll) -THIAZOLON E DYES CONTAINING E NUCLEUS Per Aubert, Oslo, Norway, and Edward B. Knott,

Harrow, England, assignors to Company, Rochester, N. Y.,

New Jersey Eastman Kodak a corporation of Application February 17, 1951, Serial No. 211,566

18 Claims.

This invention relates to photographic emulsions, methods for making,7 them, and to new nonmigratory dyes,

Photographic emulsions containing nondi1Tusing dyes have been previously described in Brooker U. S. Patent 2,282,116, dated May 5, 1942. The disadvantages attending the use of such dyes resides primarily in their staining properties when the latent image is developed.

We have now found that the prior art de cienoies can be overcome by incorporating in the unexposed photographic silver halide emulsion certain merooyanine dyes.

It is, therefore, an object of our invention to provide new photographic silver halide emulu sions. Another object is to provide methods for obtaining these new photographic silver halide emulsions. Still another object is to provide photographic silver halide emulsions containing non-diffusing sensitizing dyes, which do not cause staining on development of the latent image. Still another object is to provide new merocyanine dyes which are useful in sensitizing the aforesaid photographic silver halide emulsions. Another object is to provide methods for making these new sensitizing dyes. Other ob jects will become apparent from a consideration of the following description and examples.

According to our invention, we accomplish the above objects by incorporating a merocyanine dye containing a Z-alkylthio-Ml)-thiazolone nucleus in photographic silver halide emulsions.

The merocyanine dyes containing a Z-alkylthio-5(4)thiazolone nucleus which can advantageously be used in our invention can be represented hy the following general formula:

n-heptyl, n-octyl, ndeeyl, n-dooleoyl (lauryl),

n-tetradeoyl, n-pentadeoyl, n-hexadeoyl., stearyl, n-eioesanyl, ,6-hydroxyethyl, ,l-Chloroethyl, ,im oarbethoxyethyl, benzyl (phenylmethyl). f3phen ylethyl, v-phenylpropyl, etc. (especially an alkyl group of the formula CqHzq+1 wherein q repre 2 sents a positive integer of from 1 to 20), L represents a methine group (e. g. =CH-, zCR-,

wherein R represents an alkyl group, such as methyl, ethyl, ete), n represents a positive inn tegel' from l to 2, d represents a positiv-e integer from l to 3, and Z represents the non-uietallic atoms necessary to complete a heterooyelio nucleus containing from 5 to G atoms in the heterocyclic ring, such as heterocyclie nucleus selected from the group consisting of those of the thiazole series (e. g. thiazole, ll-methylthiazole, 4-phenylthiazole, -methylthiazole, 5-phenylthiazole, 4,5-dimethylthiazole, 4,5-diphenylthiazole, 4-(2-thienyDthiazole, ete), those of the benzothiazole series (e. g. benzothiazole, Llf-chlorooenzothiazole -chlorobenzothiazole, G-chlorobensothiazole, 7-chlorobenzothiazole, 4-inethylbenzothiazole, 5-methylbenzothiazole, 6-methylbenzothiazole, 5-bromobenzothiazole, 6-bromobenzothiazole, 4-phenylbenzothiazole, 5pheny1- benzothiazole, 4-methoxybenzothiazole, 5-methoxybenzothiazole, 6methoxybenzothiazole, 5-iodobenzothiazole, 6-iodobenzothiazole, 4-ethoxybenzothiazole, 5ethoxybenzothiazole, tetrahydrobenzothiazole, 5,6 dimethoxybenzothiazole, 5,6 dioxyrnethylenebenzothiazole, 5 hydroxybenzothiazole, 6 hydroxybenzothiazole, etc),

those of the naphthothiazole series (e, g. a-naphthothiazole, -naphthothiazole, 5-methoXy-- naphthothiazole, 5-ethoXy-,B-naphthothiazole, 8- methoxy-u-naphthothiazole, 7methoxy-anaph thothiazole, etc.), those of the thionaphtheno- 7,6,4,5thiazole series (e. g. 4methoxythionaphtheno-7,6,4,5thiazole, etc.) those of the oxazole series (e. g. 4methyloxazole, 5-methy1oxazole, 4- phenyloxazole, 4,5-diphenyloxazole, 4-ethyloxazole, 4,5-dimethyloxazole, 5-phenyloxazole, eta), those of the benzoxazole series (e. g. benzoxazole, 5 chlorobenzoxazole, 5 methylbenzoxazole, 5w phenylbenzoxazole, G-methylbenzoxazole, 5,6-dimethylbenzoxazole, 4,5-dimethylbenzoxazole, 5- methoxybenzoxazole, 5-ethoxybenzoxazole, 5- chlorobenzoxazole, 6-methoxybenzoxazole, 5hy droxybenzoxazole, S-hydroxybenzoxazole, ete), those of the naphthoxazole series (e. g. a-naphthoxazole, -naphthoxazole, etc), those of the selenazole series (e. g. 4methylselenazole, 4rphenylselenazole, etc.), those of the benzoselenazole series (e. g. benzoselenaozle, -chlorobenzoselenazole, 5-methoxybenzoselenazole, 5-hydroxybenzoselenazole, tetrahydrobenzoselenazole, etc.), those of the naphthoselenazole series (e. g. a-naphthoselenazole, -naphthoselenazole, eto.), those of the thiazoline series (e. g. thiazoline, 4- methylthiazoline, eta), those of the 2-quinoline series (e. g. quinoline, S-methylquinoline, 5- methylquinoline, T-methylquinoline, S-methylquinoline, G-chloroquinoline, 8-chloroquinoline, 6-methoxyquinoline, -ethoxyquinoline, 6-hydroxyquinoline, S-hydroxyquinoline, etc), those of the Ll-oiuinoline series (e. g. quinoline, 6- methoxyquinoline, 7-methylquinoline, 8methyl quinoline, etc.) those of the 1isoquinoline series (e. g. isoquinoline, 3,4-dihydroisoquinoline, etc.), those of the 3-isoquinoline series (e. g. isoquinoline, etc), those of the 3,3-dialkylindolenine series (e. g. 3,3-dimethylindolenine, 3,3,5-trimethylindolenine, 3,3,7 trimethylindolenine, etc.) the pyridine series (e. g. pyridine, 5-methylpyridine, etc.), etc. Merocyanine dyes wherein R1 in the above formula represents an alkyl group of the formula CqH2q+1 wherein q .represents a positive integer from 6 to 20 have been found to be particularly useful in practicing our invention in that they are substantially non-dif `fusing when incorporated in a photographic silver halide emulsion and do not give rise to stain upon development of the latent image.

'I'he dyes of Formula I above wherein d represents 1 can advantageously be prepared by condensing a compound selected from those represented by the following general formula:

a cyclammonium quaternary salt selected from those represented by the following general formula wherein R, n, and Z have the values set forth above, Y represents an electronegative group, such as chlorine, bromine, alkoxyl (e. g. methoxyl, ethoxyl, etc), or a -S--Rz group wherein R2 represents an alkyl group, such as methyl, ethyl, etc., or an aryl group, such as phenyl, o, m, and p-tolyl, etc., and X represents an anion, such as chloride, bromide, iodide, perchlorate, thiocyanate, sulfonate, methylsulfate, ethylsulfate, benzenesulfonate, p-toluenesulfonate, acetate, etc.

The dyes of `Formula I above wherein `d represents 2 or 3 can advantageously be prepared by condensing a compound selected from those represented byv Formula II above Iwith a cyclammonium Quaternary salt selected from those represented by the following general formula:

wherein R, L, n, and Z have the values -set forth above, R3 represents the vacyl group of a carboxylic acid, such as acetyl, propionyl, benzoyl, etc. (especially an acyl group of analiphatic carboXylic acid), R4 represents a hydrogen atom lor an aryl group, such as phenyl, o, m, and p-tolyl, etc., p represents va positive integer from 1 to 2, and X1 represents an anion, suchas those set forth above for X, for example.

Each of the above-mentioned condensations is advantageously carried out in the presence of an acid-binding agent, such as ythe trialkylamines v(e. g. triethylamine, tri-n-propylamine, triisopropylamine, tri-n-butylamine, tri-n-amylamine, etc.), N,Ndialkylanilines (e. g; N,N-dimethyl aniline, N,Ndiethylaniline, etc.) `N-alkylpiperidines (e. g. N-methylpiperidine, n-ethylpiperidine, etc.), heterocyclic amines (e. g. pyridine, quinoline, etc.) etc.

Inert solvents can also be present during the condensations, if desired. Typical solvents include the lower aliphatic alcohols, such as ethanol, n-propanol, isopropanol, n-butanol, etc., diethyl ether, acetone, 1,4-dioxane, n-pentane, n-heptane, benzene, toluene, chloroform, carbontetrachloride, etc. Heat accelerates the condensations, and temperatures varying from room temperature (about 25 C.) to the reflux temperature of .the reaction mixture can advantageously be employed.

The intermediates represented by Formula II above can advantageously be prepared by refluxng an ester selected from those represented by the following general formula:

V l H al-s-b-NH-CHVC-on wherein R1 has the values set forth above with acetic anhydride. The intermediates'represented by Formula II can advantageously be prepared by intermixing an aqueous alkali metal hydroxide solution, carbon disulfide, and glycine,` followed by addition of an alkyl halide to the alkali metal salt (M-s--NH-oHr--OM) formed, heating the mixture at a temperature of from about 40 to 100 C., and acidifying the reaction mixture to give the desired ester represented by Formula V above. These steps can be illustrated by the following general equations:

{BH-acid Rl-s-(HJ-NH-om-(Hi-on wherein M represents an alkali metal and X2 represents a halogen atom. This method has been previously described by Cook, Harris, Heilbron, and Shaw-Joun Chem. Soc, (London) 1948, pp. 1056-1060.

Alternatively, the merocyanine dyes of Formula I above where drepresents 2 (i. e. dimethinemerocyanine dyes) can advantageously be prepared by condensinga compound selected from those represented by the followingr general formula:

wherein R1 has the values set forth above yand R5 represents a hydrogen atom or an alkyl group (e. g. methyl, ethyl, etc. groups), with a cyclam monium Quaternary salt selected from those represented by the following general formula:

wherein R, X, n, and Z have the values set forth above. These condensations can advantageously be carried out in the presence of anv acidvdide, 2-ethylthio-5 (4) -thiazolone binding agent, such as the trialkyamines (e. g. triethylamine, tri-n-propylamine, triisopropylamine, tri-n-butylamine, tri-n-amylamine, etc), N,Ndialkylanilines (e. g. N,Ndimethylaniline, N,Ndiethylaniline, etc.) N-alkylpiperidines (e. g. N-methylpiperidines, N-ethylpiperidines, etc), heterocyclic amines (e. g. pyridine, quinoline, eta), etc. .an inert solvent can also be employed, if desired. Typical solvents include the lower aliphatic alcohols (e. methanol, ethanol, npropanol, isopropanol, n-butanol, etc.), diethyl ether, 1,4-dioxane, n-pertane, n-hexane, benzene, toluene, chloroform, carbontetrachloride, etc. Heating accelerates Athe condensations, and temperatures varying from room temperature (about 25 C.) to the reux temperature of the reaction mixture can advantageously be used.

The intermediates represented by Formula VI above can advantageously be prepared by heating together a mixture o? one of the esters represented by Formula V above, acetic anhydride, and an ortho ethyl ester selected from those represented by the following general formula:

VIII Ra-C OCzHs) 3 wherein R5 has the values set forth above. Ternperatures of from 100 to 150 C. can advantageously be used to accelerate the condensations. The following examples illustrate further the manner whereby we practice our invention.

2 ethylthio 4 ethoxymethylene 5(4) thiazolone was obtained by heating 9.0 g. of N-dithiocarbethoxyglycine on a steam bath along with 40 cc. of acetic anhydride and 12 cc. of ethyl orthoformate for 30 minutes and then distilling off liquid until an oil remained. The resultant oil was then reuxed for 5 minutes with 14.5 g. of Z-methylbenzoxazole ethiodide, 40 cc. of ethanol, and cc. of triethylamine, and the reaction mixture then chilled. The dye Was recrystallized lfrom ethanol as dat, steel-blue needles melting at It sensitized a gelatino silver chloride emulsion strongly with a maximum at 530 ma and a gelatine silver bromide emulsion with a maximum at 540 ma.

ethylthz'o 5(4) thiaeoZoneH dimethinemerocyam'ne 4.44 g. of 2--acetanilidovinylquinoline ethio- (obtained by heating 1.8 g. of N-dithiocarbethoxyglycine with acetic anhydride and driving oil the residual liquids), cc. of ethanol, and 2 cc. of triethylamine were refluxed for 5 minutes and the reaction mixture then chilled. The desired dye Was `obtained as soft, dark green needles melting at 163 C. on recrystallization from a benzene-ethanol mixture. It sensitized a gelatino silver chloride emulsion with a flat maximum lying between 530 and 590 ma.

Example 3.-[2 (3 ethylbenzoselenaeoleu [4- (2 ethylthio 5(4) thz'aeoloneH dimethinemerocyan'lne This dye was prepared in the same manner as the dye of Example 1 by replacing the 2-methylbenzoxazole ethiodide used in that example by a molecularly equivalent amount of Z-methylbenzoselenazole ethiodide. The desired dye was obtained as blue-grey prisms melting at 184 C. on recrystallizaton from benzene. It sensitized a gelatino silver bromide emulsion strongly.

This dye was prepared in the same manner as the dye of Example 1 by replacing the quaternary salt used in that example by a molecularly equivalent amount of Z-methylthiazoline methiodide. The desired dye was obtained as maroon needles melting at 129 C. on recrystallization fr0-m ethanol. It sensitized a gelatine silver chloride emulsion with a maximum at 500 ma and a gelatine silver bromide emulsion with a maximum at 530 ma.

(2 ethz'othz'o 5(4) thiaeoloneH climethinemerocyanine This dye was prepared in the same manner as the dye of Example 1 by replacing the Z-methylbenzoxazole ethiodide used in that example by a molecularly equivalent amount of 2,4-dimethylthiazole ethiodide. The desired dye was obtained as green prisms melting at 154 C. on recrystallization from a benzene-ethanol mixture. It sensitized a gelatine silver bromide emulsion strongly.

Example 6,-[4-(1-ethylquinolz'ne) l [4- (2l-ethylthz'o-5 (4) -thiaeolonw l dimethinemerocyanine This dye was prepared in the same manner as the dye of Example 1 by replacing the 2-methylbenzoxazole ethiodlde used in that example by a molecularly equivalent amount of lepidinium ethiodide. The desired dye Was obtained as blue plates melting at 143 C. on recrystallization from ethanol. It sensitized a gelatine silver chloride emulsion with a maximum at 510 ma and a gelatino silver bromide emulsion with a ilat maximum lying between 560 and 640 ma.,

This dye was prepared in the same manner as the dye of Example 2 by replacing the qua-ternary salt used in that example by a molecularly equivalent amount of 2-acetanilidovinylbenzothia zole ethodide. The desired dye lwas obtained as blue-grey prisms melting at 173 C. on recrystallization from benzene. It sensitized a gelatino silver chloride emulsion with a maximum at 550 ma and a gelatino silver bromide emulsion with a maximum at` 580 ma.

[4- (2-ethylthio-5 (4) -thiazolonw dimethinemerocylanine s o=c|1 s C=CHCH=C -S-C2H5 The dye was prepared in the same manner as the dye of Example 2 by replacing the quaternary salt used in that example by a molecularly equivalent amount of 2--acetanilidovinyl--naphthothazole ethiodde. The desired dye was obtained as flat maroon needles melting at 172 C. on recrystallization from benzene. It sensitized a gelatino silver chloride emulsion with a maximum all 560 mls.

1.8 g. of N-dithiocarbethoxyglycine, 15 cc. of acetic anhydride, and 5 cc. of ethyl orthoacetate were heated on a steam bath for one hour, and the liquids removed under a vacuum. To the residual oil were added 2.9 g. of 2-methy1benzoxazole ethiodide, 10 cc. of ethanol, and 2 cc. of triethylamine, and the whole wasv reuxed for 15 minutes and then chilled. The precipitate obtained was filtered off and recrystallized from benzene as fine, rust-colored needles melting at 118 C. It sensitized a gelatino silver chloride emulsion with a maximum at 516 ma and a gelatino silver bromide emulsion with a maximum at 540 ma.

Example 11.-[2-(3-ethylbeneothiazole)l [4-(21- eth1/limo 5(4) thiazoloneH methyldimethiaemerocyanine This dye was obtained in the same manner as the dye of Example 10 by replacing the quaternary salt used in that example by a molecularly equivalent amount of Z-methylbenzothiazole ethiodide. The desired dye was obtained as fine purple needles melting at C. on recrystal.- lization from benzene. It sensitized a gelatino silver chloride emulsion with a maximum at 550 mp. and a gelatino silver bromide emulsion with a maximum at 570 ma.

Example 12.-[2-(3-ethylbeneoselenaeole)l [4- This dye was prepared in the same manner as the dye of Example l0 by replacing the quaternary salt used in that example by a molecularly equivalent amount of 2-methylben/zoselenazole ethiodide. The desired dye was obtained as steelblue prisms melting at C. on recrystallization from benzene. It sensitized a gelatino silver chloride emulsion with a maximum at 560 ma and a gelatino silver bromide emulsion with a maximum at 570 ma.

Example 13.-[2-(3-methylthiazoline)] [41(2- ethylthio 5 (4) thiaeoloneH methyldimethz'nemerocyamne This dye was prepared in the same manner as the dye of Example 10 by replacing the quaternary salt used in that example by a molecularly equivalent amount of Z-methylthiazoline methiodide. The desired dye was obtained as grey-red needles melting at 133 C. on reerystalvlization from a benzene-petroleum ether mixture. It sensitized a gelatino silver chloridev emulsion with a. maximum at 500 ma.

9 Example 14,-[2-(Lethylqainollne)l [4-(2-eth- @Ethic-(4) -thiazolonw lmethyldz'methznemerocyam'ne This dye was prepared in the same manner as the dye of Example by replacing the quaternary salt used in that example by a molecularly equivalent amount of quinaldeinum ethiodide, The desired dye was obtained as fine green needles on recrystallization from benzene and had a melting point of 130 C. It sensitized a gelatino silver chloride emulsion with a maximum at 580 III/L.

Example 15.-[2-(3-ethyl--methylthiaaole) l [4- methlnemerocyamne This dye was prepared in the same manner as the dye of Example 10 by replacing the quaternary salt used in that example by a molecularly equivalent amount of 2,4-dimethylthiazole ethiodide. The desired dye was obtained as glossy red needles melting at 154 C. on recrystallization from a benzene-petroleum ether mixture. It sensitized both a gelatino silver chloride emulsion and a gelatino silver bromide emulsion with a maximum at 530 my.

Escample 16,-l2-(I-ethylqainoline)l [4-(2-benaylthz'o-5(4) thiazoloneu dimethz'nemerocyam'ne osC- S :CH--CHrJ (IJ-S-CHz-CuHt \N/ \N This dye was prepared in the same manner as the dye of Example 1 by replacing the quaternary salt used in that example by a molecularly equivalent amount of quinaldinium ethiodide and the 4-ethoxymethy1ene intermediate by a molecularly equivalent amount of 2-benzylthio-4-ethoxymethylene-5(4) -thiazolone The desired dye was obtained as green needles melting at 207 C'. on recrystallization from ethanol. It sensitized a gelatino silver chloride emulsion with a fiat maximum lying between 550 and 580 ma and a gelatino silver bromide emulsion with a dat maximum lying between 550 and 560 my.

Example 17.-[2-(il-ethylbenaothiazole) l [4-(2- benaylthio-S (4) thiaaolon] dimethinemerocyam'ne This dye was obtained in the same manner as the dye of Example 1 by replacing the quaternary salt used in that example by a molecularly equivalent amount of Z-methylbenzothiazole ethiodide and the 4-ethoxymethylene intermediate by a mo- 10 lecularly equivalent amount of 2-benzylthio-4- ethoxymethylene-5(4)-thiazolone The desired dye was obtained as red needles melting at 179 C. on recrystallization from ethanol. It sensitized a gelatino silver chloride emulsion with a maximum at 550 m/l.

Example 18.-[2-(3-ethylbeneoselenaeole)l [4- (2 benaylthio 5(4) -thiaaolonwl clmethz'nemerocyanine This dye was obtained in the same manner as Ithe dye of Example 1 by replacing the quaternary salt used in that example by a molecularly equivalent amount of 2methylbenzoselenazole ethiodide and the Il-ethoxymethylene intermediate by a molecularly equivalent amount (of 2-benzylthio l ethoxymethylene 5(4) thiazolone. The desired dye was obtained as violet needles melting at C. or recrystallization. from ethanol. It sensitized a gelatine silver chloride emulsion with a maximum at 560 mit.

Example 19.-[2 (3 ethylbeneoxaaolwl {4-(2- benzylthio-S (4) -thz'azolone) dimethnemerocyam'ne o o=cs Oman-elke JJ-s-Cm-ctm \N N This dye was prepared in the same manner as the dye of Example 1 by replacing the 4ethoxy methylene intermediate used in that example by a molecularly equivalent amount of 2-benzylthio- 4fethoxymethylene5(4) -thiazolone The desired dye melted at 193 C. on recrystallization from ethanol and sensitized a gelatina silver chloride emulsion with a maximum at 510 ma.

Example 20.-[2(1-ethylpy1z'dine) M42-benzylthio- (4) -thiazolon l dimethinemerocyanine Example 21.-[4-(I-ethylquinollne)] [4-(2-benaylthzo 5(4) thz'aeolone)] dimethinemerocyaulne lsalt used in'vthat [ex 'etlioxyiethylene ainterin'e dye yWals tob'tan'ed win the :same manner "as tie d'ye of yExanfipfle.,1 by replaei'rigthe Quaternary f ple byagmelcularly equivalent, mondiger iepidriiu' inname-'ane the .fi-

I t'elby La moleeularl'y equivalent amount of 2-"lenz'ylthio-4Lethoxymethylene-5(4) `thiazolon'e. 'The'des'irled dye was obtained as blue needles melting at 162 C. on recrystallization from ethanol. gelatine silver bromide emulsion with maxima at 680 and 730 me.

ythe oi x'ampleflby'replaeinggtheQuaternary salt used in that example b'yamoleulavrlyi equivalent "amount f 'zlixfrtnylthiazgiine methivod'dje and the Ll-etho:yinetldyl'ere intermediate by a molecularly equivalentarnount of 2-benzy1thio- 4ethoxymethy1ene5 (4) ethiazolone. Thedesired dye Was obtained as red-green prisms melting at 171 C. on recrystallization from a benzeneethanol mixture. It sensitized a gelatino `silver chloride emulsion Withv a maximum at 500I mp It sensitized a anda gelatino silver brmideemulsion with a f;

maximum at 525 mp.. This dye was prepared in the same `manner as the dye of Example 1 by replacing the quaternary Ysalt used inthat example bya' molecularly equivalent vambunt of 'Zimethylthiazoline methiodide .1.

andthe.,4-ethoxymethylene intermediate .by a

in'olecularly' equivalent amount of 2-:benzylthio- Aethoxymethy1ene5 4 -t'hiazolone Thev desired .dye was obtained as '.red-gree'n' prisms melting at 1719 TC. on "recryst'allizat'ion from ."a benzeneethanol mixture. `It. sensitized a gelatine silver chloride emulsieawibh.@maximum .at .500 mi anldlkauglatino. .silver bromide emulsion with a maximum at 525 my..

zole ethiodide and the` 4-ethoxymethylene"interr'nediate by' a"mo1ecularly` equivalent amefunt' of lone. The desired dye was obtained asfpurple needlesv melting at 215 C. on rystallization from a benzenefethanolmixture., I t sensitized a gelatine silver 'chloride emulsion"witha `maximum at 570 nell and 4a 'gelatino silver bromide emulsion with a maximum at 580 ma.

octyZthz'o-5(4) -thiazolonw l dimethinenerocyanine tals weighing 0.8 g. Were'eolleeted, sh ethanol and twice recrystallized from ,thisVV alcohol as small purple' needles melting at '81 vAC. It sensitized a gelatino silver chloride emulsiontwith a maximum at 500 In# and a gelatine silver bromiodide emulsion with a maximum at 520 my.

nary 'salt .used in 1 .that example, v"1031,14: g. gsmetnylphiazoline' emmerde, Y*1w/as"ettaried' 'line orange'erystals'inelting at86 4Cenfreerystalli'zation from ethanol. It `sensitized;4 `a gelatino silver chlorideeiniilsion Withaiimum atp() mea/gelatinojsilver bromiodide ernulsionwitha maximum` at 520-mp..

nary salt used in that example by 1.45 g. of 2methylbenzoxazole ethiodide. It was obtained as glittering orange plates melting at 130 C. on recrystallization from methanol. It sensitized a gelatino silver chloride emulsion with a maximum at 530 m/i and a gelatino silver bromide emulsion with a maximum at 540 mit.

This dye was obtained in the same manner as the dye of Example 25 by replacing the quaternary salt used in that example by 1.95 g. of 5-chloro-Z-methylbenzothiazole etno-p-tolulenesulfonate. It formed purple needles melting at 156 C. on recrystallization from benzene. It sensitized a gelatno silver chloride emulsion with a maximum at 560 m/L and a gelatino silver bromiodide emulsion with a maximum at 580 mit.

Example 29.-[2 (3-ethylbeneothiaeole) l [4-(2- n-octylthz'o 5 (4) -thz'aeolone) ldzmethinemerocyamne This dye was obtained in the same manner as the dye of Example 25 by replacing the quaternary salt used in that example by 1.55 g. of 2- methylbenzothiazole ethiodide. It was obtained as dark red needles melting at 81 C. from a benzene-methanol mixture. It sensitized a gelatine silver chloride emulsion with a maximum at 550 mit and a gelatino silver bromiodide emulsion with a maximum at 580 mit.

Example 30.-[2-(3-ethg/Zbeneoselenaeole)l [4- (2 n octylthzo-5 (4) thiaeolone l dimethinemerocyamne This dye was obtained in the same manner as the dye of Example 25 by replacing the quaternary salt used in that example by 1.75 g. of 2methyl benzoselenazole ethiodide. It formed glossy, ilat, violet needles melting at 86 C. from a benzenemetha-nol mixture. It sensitized a gelatino silver chloride emulsion with a maximum at 570 my and a gelatine silver bromiodide emulsion with a maximum at 590 me.

Example 31 .-[2- (S-ethylthiazoline) l [4- (Z-ethylthz'o-5 (4) -thiazolonel dimethinemerocyanine This dye was prepared in the same manner as the dye of Example l by replacing the Quaternary salt used in that example by a molecularly equivalent amount of Z-methylthiazoline ethiodide. The desired dye was obtained as yellow plates melting at 121 C. on recrystallization from ethanol. It sensitized a gelatine silver chloride emulsion with a maximum at 50i) ma and a gelatino silver bromide emulsion with a maximum at 525 mp.

Example 32.-[2-(S-ethylbeneoaeole) l [4-(2-11- dodecZythie-5 (4) -thzaeolone) l dimethz'nemerocyam'ne This dye was prepared in the same manner as the dye of Example 1 by replacing the N-dithiocarbethoxyglycine used in that example by a molecularly equivalent amount of N -dithiocarbo-nhexoglycine. The desired dye was obtained as glossy, rust-colored plates melting at 148 C. on recrystallization from ethanol, It sensitized a gelatine silver chloride emulsion with a maximum at 500 ma and a gelatine silver bromide emulsion with a maximum at 530 my.

if C 2H5 This dye was prepared in the same manner as the dye of Example l by replacing.r the N-dithiocarbethoxyglycine used in that example by a molecularly equivalent amount of N-dithioearbo-n-heptoxyglycine. The desired dye was obtained as glossy, rust-colored plates melting at 133 C. on recrystallization from ethanol. It sensitized a gelatine silver chloride emulsion with a maximum at 500 ma and a gelatine silver bromide emulsion with a maximum at 530 my.

egresada This dye was prepared in the same manner as the dye of Exam-ple `1-by "replacing the NQdithi-"ocarbethoxyglyeine used Yin that yexa'r'rme by a molecularly equivalent amount of N-dithioea'rbo- 'y-phenylpropoxyglycine. The desired dye was obtained as red crystals melting at 179 C.v lOn recrystallizationv from ethanol. It sensitized a gelatine 'silverchloride emulsin With'amaximum at 500 mfr and a gelatino silver bromide emulsion With a maximum at 530 mp.

4This dye was prepared in the same manner as the dye of -Example 10 `by l replacing the quaternary salt used in that example by a moleoularly equivalent amount of 2 methylnaphthothiazole ethiodide. The desired dye was obtained as mauve needles melti'rigat209o C. on r'ecrystallization'f'from benzene. Ilz-:sensitized a gelatine silver chloride emulsin'with a maximum at 5,50 my. and a gelatino silver bromide emulsion with a maximum at 575 mfr.

Example 37.-[2-(S-ethylbeneoxaeole) l [4-(2-n- 'de-cylthio "5 (4) thz'aeollo/ne) ldim'ethlnemero- "c1/Janine o l C=CHCH= o-s-CHz-(CHm-om `N L(IHt This dye was prepared-'in thelfsarie"iriar1fnrfas the dye of Example 1 by replacing the N-dithiooarbe'tlioxyglyeine y used in v4that example by `a nolecularly; equivalent`Y anio'ut of'N-"dithi'oeaibon-decoxyglycine. The desired dye was obtained as an orange powder melting at 106 C. on recrystallization from ethanol. -lt sensitized'a gelatino silver chloride emulsion with a/maximum at 510 vmaand a gelatine silver bromide emulsion With a maximum at 530 mp. Example 38.-[2- (3-ethylbenzoaeole) 1.[4-(2-ndec'ylthio 5 (4) thiazolofnwl ,8 'methylcli- 1 methz'nemerocyw'me }O\\ Bo l"s S-*CH'2-(CHz)s`-GH3 ,N

darbtlfoxyg'lyciie Iused Kin ithat fex'am'p'le by fa moleliiilarlfy 'equivalent "amount 'of NJ dithioca'rboni-fdeeoxyfetlyoine. 'The fdesiried dye `Was obtained as lsoft, Lvlora'rigre needles melting at'68 'C. on -recrystalliz'a'ti'on' fro'miethanol. It sensitized a gelatino ffsilve'r Yelilolde Lfdrriulsion with a maximum at 510 maand a gelatine :silver bromide emulsion With-a maximumfat 530 mu.

Example339;;[tl-(3eethylbeneomazole) l E4-'(241,-

ThisC dye was :prepared 1in thelsamerY manner as the '-dye @of 4.Example :1d-.by .replacing fthe ethyl orthoacetate used in that* example by a1m0leeularly eq-uivalentfamounti offethylorthopropionate and 7the :Nedi-thio'earb'ethoxyglycine :by f a molecularl'y equivalent amount noi -Nedi-thiocarbo-n-decoxyglycine. The ,desired dye was f obtained -as orange needles melting at 96 C. on recrystallizationffrometlianol. It sensitize'd'a gelatino silver liloride "mulsion "with "'a 'maximum at 510 my and. a gelatino silver bromide emulsionwvith a maximum at 530 mit.

:This-dye -fwaspreparedin the 4same manner asthe dye-of-Example 1 byreplacingfthe quaternary salt'usedfirl-)that` example "by: armolecularly equivalent amount of Z-methylbenzoselenazole ethiodide, and the N-ditliiocarbethoxyglycine by a -lmoleeulariy equivalent amount 4of Nadithioearboanilieptoxyglyci-ne. Thev desired dye was obtained as glossy, violet needles meltingfat-112 C. on reorystallization from ethanol. It sensitized a gelatine silver Chloride vemulsion with a maximum atnm/l `and a gelatino silver bromide emulsln'with a maximum at`585 ma.

This dye waswprepared in-the-same `marmer as the dye of Example 2 by replacing the vquaternary salt used in that example by a molecularly equivalent amount-ot2-acetanilidoelAbutadienylbenzothiazoleethiodide. rThe desiredl dye 'was obtained as a blue crystalline powder melting at 179 C. on recrystallization from ethanol. It strongly sensitized a gelatino silver 'bromide emulslon.

In a like manner, by replacing the vduaternary salt used in Example 2 by a moleoularly equivalent amount of 2-methylthiobenzothiazole ethio- 17l dide [2- (S-ethylbenzothiozole) l [4- (2-ethylthio- 5(4) -thiazolone) lmerocyanine represented by the following general formula:

\O=Cf `i C=c C-s-Czm \N l 02H5 can be obtained.

The N-dithiocarbo-n-octoxyglycine employed in Example 25 above was prepared as follows:

Example 42. N dithiocarbo n ocloxyglycine l? i Ho-C-oHz-NH-o-s-cHr-(Cnm-CH@ 22.4 g. of potassium hydroxide were dissolved in 50 cc. of water and the solution chilled. There were then added 15.0 g. of glycine and 15.2 g. of carbondisulde, and the Whole shaken mechanically until a clear orange solution resulted. A solution of 38.6 g. of n-octylbromide in 50 cc. of ethanol was added, and the mixture heated for 30 minutes on a steam bath. To the resulting one-phase solution there were added 100 cc. of water, and the cloudiness resulting removed by extraction with diethyl ether. The aqueous layer was warmed gently under reduced pressure to expel any dissolved ether, the solution chilled, and acidied with concentrated hydrochloric acid. The precipitate wascollected on a filter, washed with water, air-dried7 and recrystallized from pe-` troleum ether (B. P. 6080 C.) as glistening plates melting at 100 C.

By replacing the n-octylbromide used in the above example by molecularly equivalent amounts of n-hexyl, n-heptyl, n-decyl, n-dodecyl, and 'y-phenylpropyl halide, respectively, the following n-dithiocarbalkoxyglycines were prepared:

Example 43. Ndithiocarbo-n-hezoyglycne Obtained as glistening,` waxy plates melting at 99 C. on recrystallization from petroleum ether.

Eample 45.--N-dz'thzocarbo-n-decomyglycine HOCHzNH-S-CH2(CH2)s-CH3 Obtained as glittering plates melting at 100 C. on recrystallization from a benzene-petroleum ether mixture.

Example 46.-N-dithiocarbo-n-dodecoyglycine (Il) Il l Ho-ccHf-NH-c-s-cnr-(om),l1-CH3 Obtained as glossy plates melting at 111 C. on recrystallization from ligroin.

`Obtained as waxy plantes melting at 122 C. on recrystallization from a Ibenzene-petroleum ether mixture.

To prepare photographic emulsions sensitized with our new dyes, it is only necessary to disperse the dyes in the emusions. It is convenient to add the dyes to the emulsions from solutions in appropriate solvents. Methyl alcohol has proven satisfactory for this purpose. Ethyl alcohol can also be used. sensitization by means of these dyes is, of course, directed primarily to the ordinarily employed gelatino-silver-halide developing-out emulsions. The dyes (one or more) are ordinarily incorporated in the washed, finished emulsions and should, of course, be uniformly distributed throughout the emulsion. The concentration of the dyes in the emulsions can vary widely, i. e., from about 5 to about 100 mg. per liter of fiowable emulsion. The concentration of the dye Will vary according to the type of lightsensitive material in the emulsion and according to the eiTect desired. The suitable and most economical concentration for any given emulsion will be apparent to those skilled in the art of emulsion making. To prepare a gelatino-silver-halide emulsion sensitized with one more of these dyes, the following procedure is satisfactory. A quantity of the dye is dissolved in methyl alcohol or other suitable solvent, and a. volume of this solution (which may be diluted with water) containing from 5 to 100 mg. of dye is slowly added to 1000 cc. of gelatino-silver-halide emulsion, with stirring. Stirring is continued until the dye is uniformly distributed throughout the emulsion, With most of these sensitizing dves, 10 to 20 mg. of dye per liter of emulsion suffices to produce the maximum sensitizing elTect with the ordinary gelatino-silver-bromide (including bromiodide) emulsions. With gelatino-silverchloride emulsions somewhat larger concentrations may be required to produce the optimum sensitizing eiect. The above statements are only i illustrative and are not to be understood as limiting our invention, as it Will be apparent that these dyes can be incorporated by other methods in photographic silver halide emulsions customarily employed in the art. For instance, the dyes may be incorporated by bathing a plate of film upon which an emulsion has been coated in a solution of the dye in an appropriate solvent. Bathing methods, however, are not to be preferred ordinarily.

The accompanying drawing further illustrates our invention. Each ligure is a diagrammatic reproduction of a spectrogram showing the sensitivity of a gelatino silver bromide (speciiically a silver bromiodide) emulsion containing one of our alkylthio5(4)-thiazolone dyes. In Fig. 1, the curve depicts the sensitivity of an ordinary gelatino silver bromiodide emulsion containing [2-(3-methylthiazoline) l [4-(2-ethy1thio-5 (4) thiazolone) ldimethinemerocyanine. In Fig. 2, the curve depicts the sensitivity of an ordinary gelatine silver bromiodide emulsion containing [2- (S-ethylbenzothiazole) l [4- (2-ethylthio-5 (4) thiazolone) ldimethinemerocyanine. In Fig. 3, the curve depicts the sensitivity of on ordinary gelatino silver bromiodide emulsion containing [2- (3-ethylbenzoxazole) l [4- (2ethylthio5(4) thiazolone) ldimethinemerocyanine.

The dyes of our invention wherein R1 represents an alkyl group of the formula CqH2q+1 wherein q is a positive integer from 6 to 20 have lower solubility and diifusibility in photographic silver halide emulsions than many of the known 1sensitizing dyes and are especially valuable,

therefore, in sensitizing photographic emulsions greased (relativerl non-diiusiloilityA of the: sensitizing dyes is required for' goodf. coloreseparation; In s ornev color: processes, toog. substances-i are; present' in the emulsions that tend to dissolve the: sensitizing dyesY from the silver halide,grains.v Low; solubility of these: dyes minimizes thistendency. Typicaly color.` photographie processes; and typical; color photographic elements comprising two, or` more diierentially sensitized photographic'silver halide emulsions are described ini United States Patent 2,113,329, dated April 5;,1'93-8, inV British Patents 566,611 andV 500,862 each accepted February 10, 1939; in United States Patent 1,985,344, dated DecemberfZlQB-lg inl-United' States Patent.1,956-,122, dated April 2451934, and in United States Patent 1,511,049, dated. November 25,1924',V for example. Another case where our newlong-chain. alkyl dyes are especially1 useful-l is in the sensitization of variable contrast materials, such. as described in UnitedA States;` Patent. 2,384,598, dated September 1'1', 1945, UnitedStatesPatent 2,358,169; dated Septemberr 12, 194:4,` and; in United States Patent 2,358,060; dated September 12, 194'4..

Expulsions sensitized: according to: our inventioncanbe coated-T on thezusual': supports: of paper, cellulose acetate. lm glass' polyvinyl resin (acetate, acetal, etc.)l metal, etc.,` in the usual manner.

What we claim as-our; inventionV and desire se,- cured by'Letters Patent ofi'the United States is:

1. A photographic:silver halide emulsion, sensitized with at least' one merocyanine dye selected from those; represented the following general wherein R and R1 each represents an alkyl group, L represents-a methine group; 1r represents a positive integer from 1 to 2, d represents' apositive integer from 1v to 3', and Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus containing from'A 5- to 6 atoms' in the heterocyclic ring.

2. A photographic silver halide emulsion sensitized with at least one merocyanine dye selected from those represented by the following general formula:

wherein R represents an alkyl, group of the formulay CmHzmi-i wherein m represents a positiveinteger from 1 to 3,.R1` represents an alkyl group of the formulav CqI-Iauer wherein qrepresen-ts a positive integer froml to= 20 L represents a methine group, n represents a4 positive integer from 1` to 2, d represents a. positive integer from 1 to 3, and Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of the thiazole series, benzothiazole: series, naphthothiazole series, oxazole series, benzoxazole series, naphthoxazole series', selenazole series, benzoselenazole Series, naphthoselenazole series, thiazoline series, 2-quinoline series, 4-quinoline series, l-isoquinoline series, 3-isoquinoline series, pyridine series, and 3,3-dimethylindolenine series.

3. A photographic silver halidev emulsion sensitized with at least one merocyanine dye, selected from; those represented byI the. following general formula.;

wherein R represents, an alkyl group of the formula C'mI-I2m+1 wherein m represents a positive integer from 1 to 8, R1 represents an alkyl group of the formula CqH2q+1 wherein q represents a positive integer from 6 to 20, L represents a methine, group, n represents a positive integer from 1 to 2, d represents a positive integer from 1- to 3f, and Z represents the'non-metallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of the thiazole series, benzothiazole series, naphthothiazole series, oxazole series, benzoxazole series, naphthoxazole series, selenazole series, benzoselenazole series, naphthoselenazole series, thiazoline series, Z-quinoline series, 4-quinoline series, l-isoquinoline series, -isoquinoline series, pyridine series, and 3,3-dimethylindolenine series.

4. A photographic silver bromiodide emulsion sensitized with'` at least one merocyanine dye se-v lected from those represented by the following general formula:

r, integer from 1 to 8, R1 represents an alkyl group of the formula CqHzqgi wherein q represents a positive integer from 6 to 20, L represents a methine group',y n lrepresents a positive integer from 1V to 2 d represents a positive integer from 1 to 3, and Z represents the non-metallic atoms necessary tol complete a heterocyclic nucleus selected from the group'y consisting of those of the thiazole series, benzothiazole series, naphthothiazole series, oxazole series, benzoxazole series,

,naphthoxazole series, selenazol'e series, benzoselenazole series; naphthoselenazole series, thiazoline series, 2-quinoline series, 4-quinoline series, l-isoqu-inoline, series, 3.-isoquinoline series, Dif-ridine series, and 3,3-dimethylindolenine series.

5. A photographic silver halide emulsion sensitized with at least one merocyanine dye selected fromthose represented by tlc-1ey following general formula:

wherein R4 represents a. primary alkyl group of the. formula CmHzm-x-i wherein 'm` represents a positive integer from 1 to 8, R1 represents a priwherein R represents a primary alkyl group of the formula C'mHzmJfi wherein m represents a positive integer from 1 to 8, R1 represents a primary alkyl group of the formula CqH2q+1 wherein q represents a positive integer from 1 to 20, L represents a methine group, d represents a positive integer from 1 to 3, and Z represents the nonmetallic atoms necessary to complete a heterocyclic nucleus of the benzoxazoleseries.

'7. A photographic silver halide emulsion sensitized with at least one merocyanine dye selected from those represented by the following general formula:

wherein R represents a primary alkyl group of the formula CmH2m+1 wherein m represents a positive integer from 1 to 8, R1 represents a primary alkyl group of the formula CqH2q+1 wherein q represents a positive integer from 1 to 20, L represents a methine group, d represents a positive integer from 1 to 3, and Z represents the nonmetallic atoms necessary to complete a hetero- 25 cyclic nucleus of the benzoselenazole series.

8. A photographic silver halide emulsion sensitized with at least one merocyanine dye selected from those represented by the following general iforrnula:

wherein R represents a primary alkyl group of the formula CmHzm+1 wherein m represents a positive integer from 1 to 8, R1 represents a primary alkyl group of the formula CqHzql-i wherein q represents a positive integer from 1 to 20, L represents a methine group, d represents a positive integer from 1 to 3, and Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus of the thiazoline series.

9. A photographic silver halide emulsion sensitized with at least one merocyanine dye selected from those represented by the following general formula:

wherein R represents a primary alkyl group of the formula CmHzmJri wherein m represents a positive integer from 1 to 8, R1 represents a primary alkyl group of the formula CqH2q+1 wherein 55 q represents a positive integer from 1 to 20, L represents a methine group, d represents a positive integer from l to 3, and Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus of the naphthothiazole series.

l0. A photographic silver halide emulsion sensitized with at least one merocyanine dye selected from those represented by the following general formula:

wherein R represents a primary alkyl group of the formula CmH2m+1 wherein m represents a positive integer from 1 to 8, R1 represents a primary alkyl group of the formula CqHzq+1 wherein q represents a positive integer from 6 to 20, d represents a positive integer from 1 to 3, and Z i represents the non-metallic atoms necessary to complete a heterocyclic nucleus of the benzothiazole series.

11. A photographic silver halide emulsion 5 sensitized with at least one merocyanine dye selected from those represented by the following general formula:

30 wherein R represents a primary alkyl group of the formula CmHzm-f-i wherein m represents a positive integer from 1 to 8, R1 represents a primary alkyl group of the formula CqII2q+1 wherein Aq represents a positive integer from 6 to 20, d frepresents a positive integer from 1 to 3, and Z ,represents the non-metallic atoms necessary to complete a heterocyclic nucleus of the benzoselenazole series.

13. A photographic silver halide emulsion 0 sensitized with at least one merocyanine dye selected from those represented by the following general formula:

wherein R represents a primary alkyl group of the formula CmII2m+1 wherein m represents a positive integer from 1 to 8, R1 represents a pri- 0 mary alkyl group of the formula CqHzq-ti wherein q represents a positive integer from 6 to 20, d represents a positive integer from 1 to 3, and Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus of the thiazoline series.

14. A photographic silver halide emulsion sensitized with the merocyanine dye represented by the following formula: i

(IJzHs 15. A photographic silver halide emulsion sensitized with the merocyanine dye having the following formula:

1,A-.. 1211913. 32h13. .,rk 1132216 811111203 12126611036 Qitef, 111 the fue. 0f, this 1921311@ 1.8.. A photvegruaaphicl silver halide emulsion senstiged with the merocyanrnle dye represented by thelfqllowing in rrrlulaz :C 254 fol-foH-CHJ C-s-CZHE \N 

1. A PHOTOGRAPHIC SILVER HALIDE EMULSION SENSITIZED WITH AT LEAST ONE MEROCYANINE DYE SELECTED FROM THOSE REPRESENTED BY THE FOLLOWING GENERAL FORMULA 